14.4 Downgrading the InnoDB Storage Engine

Prior to MySQL 5.5, some downgrade scenarios involved switching the
separate instance of InnoDB known as the InnoDB Plugin back to the
built-in InnoDB storage engine. In MySQL 5.5 and higher, the
features of the InnoDB Plugin have been folded back into built-in
InnoDB, so the downgrade procedure for InnoDB is the same as the one
for the MySQL server. For details, see
Section 2.11.2, “Downgrading MySQL”.